historic concrete restoration

Historic Concrete Restoration

www.aptne.org

February 1, 2013 • St. John’s Episcopal Church

628 Main Street • Stamford, CT 06901-2094

Association for Preservation Technology Northeast Chapter


N O R T H E A S Twww.aptne.org

2013 Annual Meeting and Symposium

APTNE13

N O R T H E A S Twww.aptne.org

The Northeast Chapter of the Association for Preservation

Technology International encompasses New England,

New York State, and northern New Jersey. Our chapter

is committed to this large geographic community with

regional and local preservation events.

We invite you to learn more about our organization at

www.aptne.org.

Who We Are

APTNE13

Originally founded as the APT New York Chapter

in the mid-1980s, the organization was restructured in

2003 as the APT Northeast Chapter (APTNE) encompassing

New England, New York State, and northern New Jersey. At

present, we have approximately 110 members.

As a chapter, we conduct workshops, co-sponsor events with

local and statewide preservation organizations, and sponsor

symposia including our annual meeting. We support preservation

students by offering scholarships and outreach for student chapters.

Board Members

Christopher Dabek, President

Elisabeth Bakker Johnson, Vice President

Elizabeth Moss, Treasurer

Jack Glassman, Secretary

Elizabeth Acly

Patrick Baldoni

Jennifer Cappeto

Kent Diebolt

David Gallagher

Patrick Guthrie

Olga Hathaway

Judy Hayward

Jack Healy

Susan Hollister

Christopher Lane

Richard W. Lefever, PE

Michael Lynch

Pat Morrissey

Dan Tyler

Andrew Wilson

Benjamin Wilson

APTNE13

1Historic Concrete Restoration

Schedule of Events February 1, 2013

9:00 - 10:00 Registration

10:00 - 10:15 Welcome Chris Dabek

10:15 - 10:45 Keynote: Loving Concrete Norman Weiss

10:45 - 11:05 Mid-Century Modernist Concrete Facades Matthew Bronski

11:05 - 11:35 Break

11:35 - 11:55 Applicability of Cathodic Protection to Historic Concrete Structures Gina Crevello & Paul Noyce

11:55 - 12:15 Form and Performance: Concrete Restoration Decisions at a Modernist Icon Ken Guditz

12:15 - 12:25 The Crumbling Batteries of Fort Washington, MD: Side by Side Deterioration of Rosendale and Portland Cement Student Jeremy Robbins

12:25 - 2:00 Lunch

1:00 - 2:00 Board Meeting

2:00 - 2:20 “Made from my own hand” An Introduction to Concrete Grave Markers Stephanie M. Hoagland & Gordon Bond

2:20 - 2:40 Restoration of 12 Historic Concrete Bridges on Connecticut’s Merritt Parkways Michael Edison

2:40 - 3:00 Investigation and Testing of Archaic Elevated Concrete Floor Slabs David Schnerch

3:00 - 3:30 Break

3:30 - 3:50 Assessment of the Baltimore & Ohio Warehouse and Achieving Durability Charu Chaudhry

3:50 - 4:10 Fenway Park Renovation— Restoring the Historic Concrete at Fenway Park Ann Harrer & Paul Gaudette

4:10 - 4:20 Shocking the Rock: Cathodic Protection of Alcatraz Prison Student Katie Hammer

4:20 - 4:45 Open Discussion Chris Dabek

4:45 - 5:00 Closing Remarks Chris Dabek

5:00 - 7:00 Reception


APTNE13

2 Historic Concrete Restoration

Loving Concrete

KEY NOTE SPEAKER

Prof. Norman R. Weiss, FAPT

Why do we love concrete? Only a few decades ago, the preservation

community demonized it, expressing outrage at the monstrous

buildings and giant highways built with it. It seemed to represent the

worst of urban renewal, and thus was regarded as a threat to what

was deemed “historic” about our older cities and towns. But a new

generation of preservationists has now emerged, with a powerful

interest in mid-century modernism. Most were not yet born when

concrete construction expanded dramatically—and artistically—in the

twenty years immediately following World War II. Those structures are

now accepted as “historic” and some of them, not aging well, already

need the technical skills of building conservators. We love concrete as

an expression of 20th century design, and many of us love the com-

plexity of its unusual history and the science behind it. n

Historic Concrete RestorationSpeaker Abstracts

About …

Norman R. Weiss is a technical

specialist in the analysis and pres-

ervation of traditional building

materials. Trained as an analytical

chemist, he is recognized for his

activities in the field of masonry

cleaning and repair. He has worked

on hundreds of stone, brick and

terra cotta buildings, principally in

North America. Among his best-

known projects are the west front

of the U.S. Capitol, New York’s

Trinity Church, and Frank Lloyd

Wright’s concrete masterpieces,

Fallingwater and the Guggenheim

Museum. His current research is on

the consolidation of limestone and

marble, and the development of

novel lime-based mortars, grouts

and paints. He has taught at

Columbia University since 1977,

and is a frequent lecturer for

preservation societies and

masonry industry organizations

throughout the United States.

Prof. Weiss is Vice President of

MCC Materials, Inc. n

APTNE13


Mid-Century Modernist Concrete Facades

PRESENTED BY

Matthew Bronski, PE

This lecture will provide attendees with a thorough methodology for

investigating and diagnosing the underlying causes of deterioration in

exposed concrete facades, and developing rehabilitation approaches

and designs that both address the underlying causes of deterioration,

and are aesthetically sensitive to respecting the original design. While

the lecture will focus primarily on mid-century modernist facades,

the methodology and approach to investigation, diagnosis, and

rehabilitation are equally applicable to earlier concrete buildings.

New England has a particularly rich legacy of architecturally significant

mid-century modernist concrete (MC2) buildings. Built primarily in the

1960’s, these iconic modernist buildings are now at the age when we

have begun to regard many as historic or architecturally significant

(and thus as deserving of careful restoration and stewardship), and

also at an age where they now exhibit concrete deterioration and other

maladies from a half century of exposure to the elements. The specific

maladies (e.g., carbonation front reaching the reinforcement, high

chloride content, alkali-silica reaction, sulfate attack, etc.) that may

plague an individual mid-century modernist concrete building can

vary widely, even among buildings constructed in the same climate,

region, and time period. One must determine and fully understand

About …

Matthew Bronski, P.E., is an Associ-

ate Principal at Simpson Gumpertz

& Heger Inc. (SGH), where he has

practiced for the past 18 years. He

is the Practice Leader for Preser-

vation Technology across all five

SGH offices nationwide. Matthew

has led SGH’s exterior rehabilitation

design and/or assessment projects

efforts on numerous significant

mid-century modernist buildings,

including buildings designed by

Hilario Candela, Eduardo Catalano,

Philip Johnson, Paul Rudolph,

Eero Saarinen, Josep Lluis Sert,

Skidmore Owings and Merrill

(SOM), and Frank Lloyd Wright.

He has published over a dozen

technical papers and articles on

building facade and envelope

issues, and has served as a guest

lecturer in historic preservation or

architecture courses at numerous

universities. He holds an under-

graduate degree in engineering

(Tulane), and graduate degrees in

architecture (Penn) and historic

preservation (Penn). In 2009, he

became only the second engineer

in 113 years to receive the presti-

gious Rome Prize. n

>

APTNE13


the underlying causes and mechanisms of deterioration on a particular

concrete building in order to prescribe wholly appropriate and effec-

tive rehabilitation treatment. Consequently, thorough analysis before

intervention (as advocated by the Athens Charter of 1931) is absolutely

essential to rehabilitation work on these modernist concrete icons.

This thorough analysis and diagnosis often needs to combine:

• hands-on survey work (e.g., surveying cracks, spalls, delaminated

areas visually and through sounding with hammers and chain drag)

• in-situ testing (e.g., ground penetrating radar (GPR) surveys of con-

crete cover, corrosion potential testing using galvanostatic pulse, etc.)

• laboratory testing and petrographic analysis of concrete cores

(for concrete constituency, and evidence of internal deterioration

mechanisms such as alkali-silica reaction)

• assimilation of all of the data above, to “put together all the pieces

of the puzzle”, andunderstand the various deterioration mechanisms

at work on the particular elements of the building, and forecast

future rates of deterioration

Drawing from his extensive experience leading rehabilitation design

and/or investigation and diagnosis efforts on MC2 buildings designed

by Paul Rudolph, Hilario Candela, Eduardo Catalano, Eero Saarinen,

Josep Lluis Sert, Skidmore Owings and Merrill and others, the speaker

will describe the various maladies and deterioration mechanisms that

can befall exposed concrete, evaluate the pros and cons of different

rehabilitation options for different maladies, and describe approaches

and procedures for the ever- challenging restoration task of matching

the color and texture of uncoated (“raw”) exposed weathered concrete

with site-mixed repairs. n

APTNE13


The Applicability of Cathodic Protection to Historic Concrete Structures

PRESENTED BY

Gina Crevello and Paul Noyce

New Cathodic Protection is a corrosion mitigation technique which

entails the application of DC current through an electrolyte to

embedded steel. In the case of historic concrete structures, this can

be steel reinforcing or steel beams and columns which are surrounded

by a concrete electrolyte. The technique mimics a corrosion reaction.

In a corrosion cell, the anodic and cathodic reactions occur simultane-

ously on the embedded steel. The anodic site is where the loss of

electrons occurs and rust forms. At the cathode site, where the electrons

are gained, the steel is protected from corrosion. By installing an

external ‘anode,’ the corrosion reaction can be controlled. The external

application of electrons to the embedded steel ensures that a cathode

reaction occurs at the steel, flooding the steel with electrons, and

subsequently shifting the steel potential into immunity.

Historic concrete’s intrinsic value can be as perplexing as a corrosion

mitigation technique. Whether the concrete matrix is comprised of

unique aggregate, made to be a specific color, has a unique shape, or

is specifically coated, the aim of a corrosion repair or mitigation is to

not affect the perceived material value of the building or structure.

With the variety of cathodic protection materials on the market, one

can be left wondering which ‘system’ is the most suitable for the

historic building or structure at hand.

About …

Gina Crevello is the Principal

of Echem Consultants. She was

professionally trained at Columbia

University’s Graduate School of

Architecture Planning and Pres-

ervation in architectural materials

conservation. Upon completing

her MSc, she completed the Post

Graduate Certificate in Con-

servation of Historic Buildings

and Sites as the program’s first

certificate graduate.

She has 15 years of experience in

building diagnostics with seven

years of experience in electro-

chemical assessments, treatments

and corrosion science. She exclu-

sively focuses on corrosion failures

of steel frame and reinforced

concrete structures and material

degradation. This work includes

corrosion diagnostics, non-destruc-

tive testing, life cycle assessments,

durability engineering, and electro-

chemical remediation.

Ms Crevello has been involved with

the majority of installed Impressed

Current Cathodic Protection Sys-

tems on landmark structures in the

US to date. Her work includes iconic

structures, such as the Guggenheim

Museum and the United States

Holocaust Memorial Museum.

Gina was recently elected to the

Board of Directors for APTI and

serves a co-chair for the Training

and Education Committee. n

>

APTNE13


When assessing the use of cathodic protection to a concrete structure

with landmark status the choices of materials or anode type may be

limited or supported by the guiding preservation principles. A typical

(industrial) application where cathodic protection is used has little

aesthetic bearing, reversibility requirements or presiding conservation/

preservation guidelines. This is contrary to the repair of an historic

landmark concrete structure.

With cathodic protection, the materials and system requirements are

not always self-evident, and the installation requirements are not always

fully understood. This can be due to a number of factors, and this

presentation will aim to discuss current anode materials, installation

practicalities, and system requirements, etc.

The topics explored will cover:

• What Cathodic Protection (CP) is;

• How Impressed Current( ICCP) systems differ from

Galvanic (GCP) systems;

• What to address in system design;

• The types of anodes applicable to concrete;

• How specific anode types are installed or applied;

• What possible ‘changes’ can occur to the structure;

• How system designs can be better formulated to remain in keeping

with the historic parameters of the design team;

• The concept of ‘reversibility’ to a permanently embedded system

The final paper will aim to provide a set of guidelines that establish

best practices. This will provide a reference as to where the materials

are the best suited for a variety of historic concrete buildings. Recent

case studies from the corrosion industry and preservation industry

will be called upon as illustrations. n

About …

Paul Noyce was professionally trained as an Electrical/Electronic Engineer in Bristol, England and subsequently achieved a diploma in Electrochemistry. Paul has ex-tensive experience in the field of electrochemical corrosion re-mediation and its application to civil and historic structures. Paul’s expertise in historic building cor-rosion diagnostics, treatment and cathodic protection is unsurpassed. He has been inspirational in the use of electrochemical chloride extrac-tion (ECE), concrete realkalization, and Impressed Current cathodic protection (ICCP) in the most chal-lenging situations. Among Paul’s most notable projects are the design of Electrochemical Chloride Extraction work for the iconic Cutty Sark Clipper Ship, a grade I listed monument and the sole remain-ing clipper ship in the world; cor-rosion advisor to the Guggenheim Museum, and the first use of Cathodic Protection to heritage structures in the UK (Joshua Hoyle Building) and the United States (Marshall Field’s Flagship).

Paul has provided corrosion diag-nostics, design engineering and installation support to over 100 ICCP systems for historic buildings in England and the US. He has pro-vided assessments and alternative electrochemical treatments to con-crete structures, from the historic Hoover Building in London to new LEED Certified Structures where ASR has led to early deterioration.

Additionally, Paul has designed and overseen the installation of the largest CP systems for rein-forced concrete installed to date in North America at the Crystal River Nuclear Facility, Crystal River Florida.

Paul sits on numerous NACE and ACI committees, has published exten-sively, and has more than 25 years practical experience with CP instal-lations. He is the chairman of NACE’s Committee TG 044 for the use of ICCP on reinforced concrete. n

APTNE13


Form and Performance: Concrete Restoration Decisions at a Modernist Icon

PRESENTED BY

Ken Guditz, AIA

The focus of this talk will be how a project team made actual preserva-

tion decisions for repair, replacement, visual restoration, and long-term

protection of precast and in situ concrete at a fifty-year-old modernist

icon. The intent is to show how conservation and replacement decisions

were made in the context of cost, schedule, and appearance following

a comprehensive condition assessment and failure diagnosis by others.

The architect’s exploration of alternative approaches to disassembly,

spall repairs, reuse of embedded anchors, component replacement,

and cleaning could guide others working with historic buildings of

similar construction.

Josep Lluis Sert’s School of Law and Education Tower at Boston

Univerity was one of the architect’s most sculptural compositions

among the buildings of his legacy in New England. Sert based the

building’s composition on fields

of stacked, repetitive, precast

assemblies featuring three-

dimensional arrays of precast

fins and scuppers that project

from a simple geometric core

of in situ concrete.

The building’s construction

consisted of a straightforward

frame of columns and slabs

that were infilled with pre-

cast concrete spandrels, sills,

scuppers, and full-height fins.

Multi-paned steel windows,

floor-height-vent panels, and

frameless glazing were framed

directly into the concrete

and their weather resistance

depended almost entirely on

a single line of caulk. Monolithic

concrete panels were all that

stood between classroom

and office interiors and the

world of driving rain and

freezing winters.

About …

Ken Guditz, AIA, LEED AP

As an Associate with Bruner/Cott,

Ken has extensive experience

in the restoration and adaptive

use of historic structures of both

local and national significance.

He has managed a wide range of

high profile preservation projects

in Boston including the Hatch

Memorial Shell, the Wang Center

for the Performing Arts, the

Christian Science Publishing

House, as well as the Nott Memo-

rial at Union College and the U.S.

Federal Courthouse and Post

Office in Old San Juan, Puerto

Rico. He is currently the Pres-

ervation/Technical Manager for

the School of Law renovation at

Boston University, an update of

Josep Lluis Sert’s mid-century

Modern complex in Kenmore

Square. Ken received a Bachelor

of Architecture and a Bachelor

of Science from Rensselaer Poly-

technic Institute and a Master of

Arts in Preservation Studies from

Boston University. n

>

APTNE13


Restoration of the BU Law Tower involved removal of ruined precast

fins along with wholesale replacement of windows and opaque vent

panels. Analysis of the assembly sequence and anchorages for each

element of the façade involved on-site demolition to compare what

was built to the 1959 construction documents and to assess the

condition of fasteners.

The presentation will compare field trials for cleaning and sealing

different concrete surfaces, describe investigative disassembly to

discover how to remove and insert individual elements within the

façade, and discuss financial aspects of different techniques.

The architectural investigations followed by design and specification

for rehabilitation benefited from Simpson Gumpertz & Heger’s prior

condition assessment of the façade and laboratory testing that

identified typical failure modes and their extent along with projected

time-lines for longer-term deterioration.

Sub-contractors’ involvement in mock-ups, disassembly and value

engineering was helpful and suggests methods to consider for

working with construction management teams on future projects. n

The Crumbling Batteries of Fort Washington, MD: Side by Side Deterioration of Rosendale and Portland Cement

PRESENTED BY

Student: Jeremy Robbins

At one time an integral artillery emplacement guarding the only coastal

access to the nation’s capital, the batteries at Fort Washington fell into

permanent ruin following their obsolescence by the time of the First

World War. Originally constructed in the early 1820’s after the American

garrison intentionally destroyed the preceding fortifications during

the War of 1812, Fort Washington saw several periods of disuse and

subsequent remodeling. Although the fort complex has become a

national park, the National Park Service has never identified an appropriate

use for the massive concrete structures. The eight batteries at Fort

Washington has long since seen their guns removed. Their windows and

doors broken and their concrete walls and slabs crumbling, the derelict

batteries remain a low priority as cultural resources. However, the struc-

tures retain significant value for the wealth of information they contain

for the preservation of historic concrete.

About …

Jeremy Robbins is delighted to

return as a student presenter for

APTNE. Currently a second year

graduate student in the UMass

Amherst program in Design and

Historic Preservation, Jeremy

also holds a masters degree in

Private School Leadership from

the Klingenstein Center at Teach-

ers College, Columbia University.

He is a graduate of the College

of Letters at Wesleyan University.

He currently serves as Director

of Camp Dunnabeck at The

Kildonan School in Amenia, NY,

which is a summer academic

program for children with dyslexia.

Jeremy is an avid woodworker

and treehouse designer; he also

plays banjo and sings in a blue-

grass band called Grass Fed. n>

APTNE13


In 1978, National Park Service historian Gary Scott authored a segment in

the APT Bulletin titled “Historic Concrete Preservation Problems at Fort

Washington, MD.” Scott cites a structural condition survey conducted

by a consulting engineer James Madison Cutts, who determined the

conservation issues and made recommendations for methods of preser-

vation. The massive sections of the fortifications were designed to hold

up against post-Civil War artillery fire. Less massive reinforced concrete

components supported secondary functions. As the fort was constructed

of both Rosendale and Portland cement elements, the deterioration

various significantly, depending on the type of cement used. Water

infiltration and freeze and thaw cycles have caused most of the concrete

deterioration, resulting in spalling of the concrete surface and lateral

movement of slabs. Corrosion of ferrous elements in reinforced sections

and vegetative growth have also resulted in further cracking and splitting.

This paper will pick up on the work of Scott and Cutts some 35 years

later, incorporating a turn of the century comparison between physical

tests and chemical analyses of samples of Portland and Rosendale

cements completed for the New York section of the Society of Chemical

Industry of England, May 25, 1900, as well as documenting what remains

of the hundred year old structures. While the massive concrete sections

were designed to withstand the ravages of enemy fire, it is the forces

of nature that are ultimately reducing the batteries to rubble. These

crumbling structures have the potential to provide unparalleled insight

into early concrete construction and its preservation. n

APTNE13


“Made from my own hand” An Introduction to Concrete Grave Markers

PRESENTED BY

Gordon Bond & Stephanie M. Hoagland

Walk through some urban cemeteries and out back, beyond the fancy

marble gravestones and grand granite monuments, you may find

personal expressions of memorialization cast in concrete. Historians

Gordon Bond and Stephanie M. Hoagland noticed these evidently

homemade grave markers while exploring New Jersey’s cemeteries

and decided to research the stories behind them. What they discovered

was a little-studied and under-appreciated form of funerary folk art.

Calling them “folk grave markers,” Bond and Hoagland found that they

were primarily created in the first half of the 20th century, peaking

between the 1910s and 1930s, despite the long-established availability

of commercially manufactured markers. While encompassing a variety

of materials, such as wood, metal, terra cotta, etc., the majority were

made from concrete. They reflect a vernacular history of then-recent

European immigrants, with most examples found in Catholic cemeteries

and largely urban, working class communities. A combination of estab-

lished funerary traditions and economic stresses likely account for the

choice to make their own markers. But once determined, it is probably

not coincidence that so many opted to use concrete. The early 20th

century saw concrete emerge as a respectable construction material

in its own right. Architects no longer felt they had to hide their use of

it. Concrete was economical, available, and workable, yet also durable,

making it an attractive option.

While folk grave markers were made by amateurs, these people were

sometimes skilled or semi-skilled working in masonry. Forms range from

simple, unadorned tablets or crosses to complex designs incorporating

inscribed and embedded decoration. Some are highly artistic, reflecting

the skill and creativity of the makers. By paying attention to tell tale

marks or asymmetries introduced by the wood molds used in casting,

Bond and Hoagland noticed the same molds had been used for different

families. Overall shapes are found to have been copied from professionally

made markers as well as other folk markers, lending community-specific

flavor to designs within cemeteries.

Concrete folk markers are not exclusive to New Jersey, however.

Examples have been found throughout the northeast United States

(and elsewhere) as well as up into Canada. While the cultural back-

grounds may be different, the same economic dynamics appear to

be at work as well as the availability of concrete.

About …

Gordon Bond is the ePublisher of

www.GardenStateLegacy.com, a

quarterly online magazine dedi-

cated to New Jersey history. As an

independent historian, author, and

lecturer, he has written many New

Jersey related articles and two

books, “James Parker: A Printer

on the Eve of Revolution” (Garden

State Legacy, 2010) and “North

Jersey Legacies: Hidden History

from the Gateway to the Skylands”

(History Press, 2012). He is pres-

ently working on a book about the

1951 Woodbridge, NJ train wreck

and “Hidden History of South

Jersey: From the Capitol to the

Shore” (History Press, Fall 2013).

Other areas of research include

New Jersey’s folk grave marker

traditions and leading a team

proposing an archeological

exploration of the Thomas Mundy

Peterson house site in Perth

Amboy, NJ. A proud native of the

Garden State, he lives with his

wife, Stephanie M. Hoagland and

their two cats in Union Township,

New Jersey.

Stephanie M. Hoagland is a partner

at Jablonski Building Conserva-

tion, Inc. where she has worked

for the last 9 years. She gradu-

ated from Columbia University

with a Masters Degree in Historic

Preservation. After graduation she

worked at ARCH2 in Metuchen,

New Jersey where she surveyed

and wrote the multiple property

and historic district nomination

forms for the Wildwood Shore

Resort Historic District which at

the time included a collection

of over 200 1950s and 60s-era

motels. At JBC she was worked

on conserving structures > >

APTNE13


across North America from the

Colonial Building in St. John’s

Newfoundland to gold rush-era

cemeteries at Marshal Gold

Discovery State Historic Park

in Coloma California. When not

working to preserve historic

architecture, she is collaborating

with her husband, Gordon Bond,

on a survey of New Jersey folk

grave markers. n

Unskilled makers, how-

ever, often introduced

unintentional flaws that

would result in eventual

condition issues. Use

of ferrous materials as

reinforcement—or no

reinforcement in the first

place—presents unique

preservation and conser-

vation issues. Bond and

Hoagland have noted

multiple markers where the conditions have rapidly deteriorated within

just the few years that they have been studying them.

Bond and Hoagland’s presentation will introduce the historic use of

concrete as a material for grave marker creation and the preservation/

conservation issues associated with the practice. n

About …

Stephanie M. Hoagland, continued

Restoration of 12 Historic Concrete Bridges on Connecticut’s Merritt Parkway

PRESENTED BY

Michael P. Edison

The Merritt Parkway in southeastern

Connecticut is a 37-mile long historic

highway constructed in the late 1930’s.

It is listed in the National Register of

Historic Places. Of particular architectural

significance are the Parkway’s concrete

bridges and overpasses, each of which

was designed to be unique in appearance.

In February, 2009, restoration of twelve

of the Parkway’s historic concrete bridges

was begun with funding from the American

Recovery and Reinvestment Act, the federal

economic stimulus program. Work was

completed in late summer 2012.

The goals of the restoration project included

not only functional stabilization, as all but

one remain traffic-bearing structures,

but also retention of the unique aesthetic characteristics of each of the

bridges. To this end, the project began with petrographic analyses of >

APTNE13


cores taken from each of the bridges, from which variable depth repair

mortars and replication mixes for sections of replacement concrete

could be designed.

Special consideration also had to be given to matching of colors,

textures and weathering patterns, and a series of custom-matched

stains and coatings were developed to aid in achieving aesthetic

objectives. The wide variation in concrete colors, including distinct

carbonation stains on some structures, presented particular challenges.

Yet another consideration was the integration of replacement elements

into partially remaining original structures. On-site worker training was

a critical component in actualizing the intended aesthetic results.

Other challenges encountered in the course of the work included

frequent graffiti attacks on cleaned structures. Ongoing graffiti

management issues had to be addressed in a manner feasible for

CTDOT maintenance personnel, while preserving the historic fabric

of the bridges to the maximum extent possible.

While the project was successful, lessons were learned in the course

of its execution and are to be incorporated into the program to restore

the next group of historic Merritt Parkway bridges, scheduled to begin

in 2013. n

About …

Michael P. Edison, chemical

engineer, is Founder and President

of Edison Coatings, Inc. in Plain-

ville, CT. Over the past 32 years

the Company has formulated and

produced customized repair mor-

tars and coatings for thousands of

concrete and masonry restoration

projects on 6 continents.

Edison is a Past President of the

Connecticut Chapter of the Inter-

national Concrete Repair Institute,

a past Director of the Association

for Preservation Technology North-

east Chapter and a former Chairman

of the Central New York Section of

the American Institute of Chemical

Engineers. He is currently Vice

President of the Society for the

Preservation of Historic Cements

and Chairman of ASTM Task Group

C1.10.04 on Natural Cement. n

Investigation and Testing of Archaic Elevated Concrete Floor Slabs

PRESENTED BY

David Schnerch, PhD, SEd

Numerous types of innovative floor construction systems were developed

in the early 1900s when fire protection of buildings became a critical

issue and structural design with reinforced concrete was relatively new.

The present adaptive reuse of buildings constructed in this period has

resulted in the need to evaluate these early systems to determine if

they are suitable for current code-mandated floor loads. Investigation

and testing is often the best way to confirm their capacity, particularly

when drawings showing the floor construction and indicating material

strengths are not available. A case study will be used to discuss these

topics as they are related to a four-story, steel-framed building with

concrete floor slabs that was constructed in the early 1900s. This

building is currently being restored for use as office and retail space

in Boston’s Back Bay neighborhood. >

APTNE13


About …

Dr. David Schnerch, since joining

WJE in 2005, has completed a

wide range of structural evalua-

tions, failure investigations, load

tests, and repair designs of build-

ings, bridges, parking garages,

tunnels, and other structures. This

work has included the evaluation of

reinforced, prestressed, and post-

tensioned concrete, as well as

masonry, steel, and wood structures.

Before joining WJE, Dr. Schnerch

studied the repair of concrete

and steel structures using ultra-

high modulus fiber reinforced

polymer (FRP) materials. This work

focused on the development

of practical solutions for repair

and strengthening of existing

structures and has been published

in the ASCE Journal of Bridge Engi-

neering, Transportation Research

Record: Journal of the Transpor-

tation Research Board, and other

publications. n

Initial investigation of the

concrete used to construct floor

slabs found that the compressive

strength is relatively low and

would not be adequate for the

required floor loads currently

required. Non-destructive tech-

niques were used to determine

the configuration of the existing

reinforcing in the slabs. Several

locations where there are exist-

ing pipe penetrations through

the floor were reviewed and an

additional small opening was

made to determine the floor

construction. It was found that

the floor was constructed of

cinder concrete, containing ash

from the burning of coal as part

of its composition. Unlike mod-

ern slabs with deformed reinforcing bars or wire mesh, the reinforcement

consists of flat bars oriented on edge at 16 inches on center. This system

is consistent with an early form of reinforced concrete floor construction

known as the Roebling Flat Slab Floor.

Proof load testing was performed at the ground and second floors to

confirm the strength of the floor slab in accordance with the require-

ments set forth in ASTM E196-06 Standard Practice for Gravity Load

Testing of Floors and Low Slope Roofs. Uniform loading was applied in

the test area using wood tanks that were filled with water in increments

up to a load of 200 pounds per square foot (twice the desired specified

floor load) and maintained on the slab for a period of twenty-four hours.

Electronic instrumentation consisting of cable extension transducers

and dial gauges were located on the floor below the tested floor to

continuously record the deflection of the slab during each increment of

load application. Deflection of the floor system was found to be small

and elastic, such that the floor returned to its original position after

removal of the load. The results of testing were compared to empirical

formulas developed by Columbia University and the Bureau of Buildings

in New York for this type of floor system. This method presents a possible

approach to evaluate floor load in project of similar construction to the

case study project. n

APTNE13


Assessment of the Baltimore & Ohio Warehouse and Achieving Durability

PRESENTED BY

Charu Chaudhry, LEED AP

Concrete often undergoes significant alterations in its microstructure

and mechanical properties while interacting with its immediate environ-

ment. The consequences are adverse and if left unattended, can lead

to cracking and delamination of the material. The concrete mineralogy

is sensitive to temperature and thermal cycling, particularly during the

early hydration period. As a result, the durability of the concrete system

and their constituent phases is compromised. Many intrinsic factors and

external weathering agents have contributed to the active corrosion and

large scale concrete deterioration at the Baltimore and Ohio terminal

warehouse. The building was built in 1910 in an industrial neo-classical

style and was intended to streamline the operations of the Baltimore

and Ohio Railroad along the Hudson River waterfront. At the time of its

opening, it was said to be the largest concrete framed structure in New

York City and the first to employ flat slab construction (with no interior

beams) technique. Today the building is still being used as a storage

facility and is a surviving example of the industrial architecture and

freight-related activity in West Chelsea during the early-twentieth

century. During the investigative phase, the exterior concrete was

carefully sound-tested with a small hammer to detect voids associated

with sub surface cracking, delamination, freeze-thaw damage and

About …

Charu Chaudhry, LEED AP is an

expert member of the International

Scientific Committee on Earthen

Architectural Heritage, ICOMOS

ISCEAH. She is also a member of

sustainable preservation technical

committee of Association of

Preservation Technology Interna-

tional. She was awarded Charles

Wallace Conservation Fellowship

for conservation training in

advanced applications of lime

technology and stone conserva-

tion in the UK and USICOMOS

internship in the U.S. She currently

serves as an architect in the Build-

ing Performance Group at Thornton

Tomasetti in New York. She has

experience in design and man-

agement of preservation projects,

including conditions surveys,

historic research, materials con-

servation, testing and technical

specifications. She has authored

several peer-reviewed papers in

the field of earthen architecture,

climate change and grouts. n

>

APTNE13


spalled areas and previous repairs. A pigmented coating was also

observed throughout the extent of the building. Many cracks and spalls

in the coating were also observed. Research was undertaken to identify

original construction through drawings and historic photographs.

Following, a laboratory testing program was devised to understand the

properties of the historic cement and aggregate and restoration strategies

were formulated. The investigative phase also revealed concentration of

cracks and spalls along the window heads, sills and jambs. This cracking

was caused due to expansive forces caused by corrosion of embedded

reinforcing steel. The corrosion of the reinforcing steel in concrete occurs

when chlorides enter the concrete and cause a breakdown of the passive

oxide film around the steel. A second form of corrosion through car-

bonation was also identified. Carbonation has subsequently reduced

the alkalinity in the concrete. Other type of cracking and delamination

observed was adjacent to previously conducted repairs. Most of the

previous concrete repair areas were found to be cracked, delaminated

or debonded revealing the embedded reinforcing steel. The reinforcing

bars were twisted square bars commonly used in 1910s. The reinforcing

steel was used with minimal cover permitting the steel to be exposed

to the moisture in the carbonated concrete and therefore permitting it

to corrode even further. A concentration of calcium carbonate was also

observed along the south façade around the cornice level, indicating that

water migrating through the concrete body has leached out calcium car-

bonate and deposited on the surface. The paper will present the findings

of the survey, various stages of deterioration revealed and subsequent

restoration strategies formed. n

Fenway Park Renovation—Restoring the Historic Concrete at Fenway Park

PRESENTED BY

Ann Harrer and Paul Gaudette

Fenway Park, opened in 1912, is the oldest

stadium in Major League Baseball. Fenway

was designed by Osborne Engineering Company,

one of the premier stadium designers of the

early twentieth century and the firm that also

designed the original Yankee Stadium (New

York) and Wrigley Field (Chicago). Since the

opening of the stadium in 1912, there have

been several additions and modifications,

some due to fires similar to those that plagued

other early stadiums. >

APTNE13


The investigation and development of repair techniques for Fenway

Park included a collaboration of architects, engineers, conservators,

contractors, and craftsman. The results of the investigation and

laboratory analysis were applied in the development of multiple mix

designs, shop samples, cleaning samples and trial repairs prior to the

construction phase.

The presentation will focus on renovation of the original seating bowl

(1912), grandstands (1934), and bleachers (1934). The project was

conducted as part of four-year phased repair program that is part of a

master plan for renovating the stadium. The master plan was developed

by the new ownership in 2002 in lieu of replacement of the stadium.

The repair program was completed in time for the 100th anniversary

of Fenway Park in 2012.

The seating bowl is constructed of concrete tread and riser sections

supported by concrete framing. Structural steel framing supports the

upper levels of the stadium, which consist of metal deck and concrete.

The underside of the sections constructed in 1934 is a tread and riser

system, while the 1912 original seating bowl was constructed with a

sloped concrete slab with a visible formboard finish. During the repair

program the historic concrete of the concrete seating bowl, including

the color, profile, and formboard finish, was to be repaired to match

the original concrete.

Renovations to the seating bowl include underside concrete

repairs to replicate and match existing adjacent concrete. As part

of the presentation, discussion will address assessment techniques,

restoration strategy, and repair of architectural and historic elements

of the park. The presentation will include discussion and examples

of repair techniques used, including matching of repair work to

original materials, field repair trials, the cleaning program, and

various approaches to repair of the historic elements high. n

About …

Ann Harrer, PE, is a Senior Associate

with Wiss Janney Elstner Associates,

Inc., in Los Angeles, California

(previously of Boston, Massa-

chusetts). Her work focuses on

investigation of historic and con-

temporary masonry and concrete,

materials assessment, and repair

and rehabilitation design. She is a

member of APTI, APTNE and ACI

Committee 546, Repair of Concrete.

Paul Gaudette, FACI, FAPT, is a

Principal at Wiss Janney Elstner

Associates, Inc., in Chicago,

Illinois. His work focuses on

investigation of historic and

contemporary concrete concrete

materials assessment, and repair

and rehabilitation design. He is

co-author of Preservation Brief

15: Preservation of Historic Con-

crete, and is recent past Chair of

ACI Committee 546, Repair

of Concrete. He has led five

workshops for the Association

for Preservation Technology

International on Repair of Historic

Concrete. n

APTNE13


About …

Katie Hammer is a fourth-year

student at the University of

Maryland where she is majoring in

Civil Environmental Engineer-

ing. She is interested in studying

how environmental factors affect

our existing infrastructure, and

what measures can be taken to

preserve the structural integrity

of these buildings for the future.

She has had the opportunity to

study abroad in New Zealand and

China, which has given her a

broader perspective of issues

dealing with civil engineering.

Katie has worked with Electro-

techCP and Structural on projects

dealing with performing corrosion

surveys and designing cathodic

protection systems. Some projects

include Alcatraz Prison in San

Francisco, CA; Dockside Con-

dominiums in Charleston, SC;

and the coal dock at Progress

Energy Power Plant in Crystal

River, Florida. n

Shocking the Rock: Cathodic Protection of Alcatraz Prison

PRESENTED BY

Student: Katie Hammer

The use of cathodic protection as a corrosion mitigation technique for

reinforced concrete structures is becoming increasingly prevalent as

society realizes the importance of preserving our nation’s heritage. For

aging structures, exposure to natural elements over a long period of time

can lead to corrosion. Eventually the corrosion can lead to a variety of

failures to the loss of structural integrity of the building. As historic

buildings have a higher intrinsic value, minimizing loss and damage to

the original fabric should be the driving force of a repair. The application

of a cathodic protection system can assist in minimizing these damages,

as seen in the recent work at Alcatraz.

Alcatraz Prison, a landmark rich in American history, is seeing the

damaging effects of a lifetime of exposure. Alcatraz was first constructed

in the 1850’s, and has since been used as a military fortress, a prison

holding America’s worst criminals, a Native American Reserve, and is

currently a historic landmark governed by the National Park Service.

Alcatraz Island, located in the San Francisco Bay is constantly exposed to

seawater, marine mist, wind, and rain. The deterioration has led to spalling,

cracking and delamination of the concrete. The installation of a cathodic

protection system will prevent further corrosion of Alcatraz’s cellblocks

and shower cells, which in turn protects the unique and historic qualities

of the prison.

Corrosion is an electrochemical process that occurs when external

environmental factors break down the protective layer that naturally

surrounds steel embedded in concrete. Carbonation and chloride attack

are the two processes which break down this passive layer: both caused

by water or salt reaching the steel. The corrosion reaction involves the >

APTNE13

movement of an electrical charge

from an anode (positively charged

area of the steel) to a cathode

(negatively charged area of the

steel), resulting in rust at the

anode site.

Cathodic protection provides an

external anode, which leads to all

of the reinforcing steel becoming

the cathode. In an impressed

current cathodic protection system,

a power supply applies a direct

current (DC) to the steel via a

permanent anode fixed to the

surface of the concrete. This

current stops the anodic reaction

(rust-forming reaction), forcing the

cathodic reaction at the steel. Con-

tinuous application of this current protects the embedded steel

from future corrosion. The installation of a cathodic protection system

requires little-to-no destructive measures, can be easily hidden to

protect the aesthetics of the structure, and protects the masonry and

concrete from further corrosive damage.

The prison cells on Alcatraz Island are just one of the many examples

of historic reinforced concrete structures that need protection against

corrosive elements. As the modern masterpieces of the 1950s and

1960s become landmark structures, this technology has a wide range

of applicability to irreplaceable historic concrete buildings.

The poster or talk will further illustrate the problems at Alcatraz, the

type of cathodic protection system designed, and the benefits of

cathodic protection for historic concrete buildings. n


APTNE13


Notes:

APTNE13


APTNE13 A Special Thank You to our Sponsors

Event Sponsors

Platinum Level Sponsors

Gold Level Sponsors

Silver Level Sponsors Reception Sponsor


N O R T H E A S Twww.aptne.org2013 Annual Meeting

and Symposium

Event VendorsCathedral Stone Products

Conproco Corp.

Deerpath Construction.

Edison Coatings, Inc.

ICRI Connecticut Chapter

KEIM Mineral Coatings of America

Micro-Cotta

Prosoco, Inc.

Brochure Design Deborah Bush

[email protected]

menders, torrey & spencer, inc.

123 North Washington Street, Boston, MA 02114

w w w . m e n d e r s a r c h i t e c t s . c o m

architecture preservation

KAESE & LYNCHARCHITECTURE

AND ENGINEERING LLP

February 1, 2013 • St. John’s Episcopal Church

628 Main Street • Stamford, CT 06901-2094

historic concrete restoration

Documents